Jersey Knit Sleepwear

jersey knit
Jersey is a knit fabric used predominantly for clothing manufacture. It was originally made of wool, but is now made of wool, cotton, and synthetic fibres.
This fabric has a definite smooth side, the outside, and a textured side, the inside.
A single-knit, plain-stitched fabric with a face side that is markedly different from the back side.

sleepwear
nightwear: garments designed to be worn in bed
Pajamas or other clothing suitable for wearing in bed